Started with this, when the PM was interrupted in the Parliament by the audience singing Grandola Vila Morena, now each time a Minister is making a public appearance, people do the same, forcing them to stop talking, in one case in a university conference the minister had to cancel the speech.

To give some context, this is not just a random song, it was the song that was broadcast on 25th April 1974 on the Portuguese radio as the signal to start the revolution.